The clinical practice recommendations of the American Diabetes Association propose the use of glucagon-like peptide-1 (GLP-1) receptor agonists and pioglitazone, two drugs currently available to treat obesity and type 2 diabetes, for the dual purpose of treating non-alcoholic fatty liver disease (NAFLD) in patients with obesity or type 2 diabetes, as endorsed by other medical societies [5–8]. The gene discussed is GLP1R; the disease is obesity due to melanocortin 4 receptor deficiency.